Communications systems generally transfer information between a source and a destination. An exemplary two-way communication system 100 is illustrated by FIG. 1A. The communication system 100 includes a network 110 (e.g., a paging system or other messaging system) and a wireless communication device 120 (e.g., a pager or other mobile wireless communication device). The communication system 100 also includes a transmitter, such as base transmitter 111, and a receiver, such as base receiver 112, which transmit and receive information signals over some media, respectively. This media may be cable wiring or the atmosphere, for example. When communications occur over the atmosphere, or air waves, they are commonly referred to as "wireless" communications. Examples of wireless communications systems include digital cellular, packet data paging, digital cordless telephones, wireless modems, wireless local and wide area networks, digital satellite communications and personal communications networks.
Returning to FIG. 1A, the base transmitter 111 is typically mounted to a tower that is 120 to 800 feet high and is significantly more powerful than the transmitter of the wireless communication device 120 which is typically located approximately 3 feet from the ground. Consequently, the distance at which reliable message exchange can take place from the base transmitter 111 to the wireless communication device 120, labeled R1, is much greater than the distance at which reliable message exchange can take place from the wireless communication device 120 to the base receiver 112, labeled R2. Therefore, one of the many challenges faced by designers of communications systems and wireless communication devices is how to resolve the imbalance in bit-error rates between the forward channel (i.e., the path from the network 110 to the wireless communication device 120) and the reverse channel (i.e., the path from the wireless communication device 120 to the network 110).
One prior technique for balancing the in-bound and out-bound bit-error rates in a two-way paging system is illustrated by FIG. 1B. According to this technique, the problem is solved with an appropriate network design. In this example, the network topology is designed such that whenever a wireless communication device 120 is within range of a base transmitter 111, it will also be within range of a base receiver 112. However, it should be appreciated this solution is extremely costly. Further, since occasional lapses in coverage on the reverse channel are tolerable for pager users, the additional expense to make the forward and reverse channel coverage areas identical is not cost effective.
What is desirable, therefore, rather than additional receivers per transmitter, is a mechanism for distinguishing between the various coverage combinations and for effectively conveying the current service level (e.g., the current capabilities of the wireless communication device) to the user. Advantageously, in this manner, the user of the wireless communication device will have the appropriate expectation of his/her current ability to originate and/or receive messages by way of the wireless communication device. Additionally, it is desirable to use this same mechanism as a foundation for the wireless communication device's registration processing.